1. Field of the Invention
The present invention a method for data and signal transfer between different sub-units of a medically-related system, in particular a CT system, as well as a medically-related system in which the method is implemented.
2. Description of the Prior Art
Medically-related systems, in particular modern CT systems, include a number of connection lines between the individual sub-units, via which signals are transmitted for the activation of components of the system, as well as for the transfer of digital data such as, for example, measurement data. Due to the continuing development, CT systems require a flexible and expandable architecture that should be directed toward high reliability as well as toward a simple implementation of service tasks, and additionally should limit the cost expenditure for expansions.
Just like the other, medically-related systems, for example in the field of magnetic resonance tomography, the architecture of currently used CT systems is based on the use of a standard control network such as, for example, CAN (Controller Area Network) for the transfer of digital data with low speed. Furthermore, numerous additional connection lines are used via which (respectively based on a separate protocol and a separate specification) logic signals are transferred, usually in analog form. In particular signals that must be frequently and very quickly updated during the system operation (such as, for example, control signals) are transmitted via these latter connection lines. This leads to a multiplicity of connections with respectively different protocols that make future improvement and expansion of such a system more difficult.
U.S. patent application Pub. No. 2003/0214953 specifies a method for data and signal transfer between different sub-units of a medical system in which communication is effected between master nodes and slave nodes via a network. The master or slave nodes are associated with different sub-units of the medical system. This published application discloses the use of a uniform communication protocol for the data and signal transfer between the individual nodes. The CAN and the CAN OPEN network are proposed.
German OS 195 41 441 discloses an apparatus for transfer of data between the rotating part and the stationary part of a computed tomography apparatus. The apparatus has a carrier generator unit to generate first and second carrier signals with an adaptable phase shift angle between one another that corresponds to an externally acquired control signal, and a modulation device to receive an externally acquired data signal, for example image data, in order to generate first and second modulated output signals with a selectable phase angle difference. The phase angle difference is selected in order to prevent formation of leakage signals due to a misalignment between the coupler and the transmission line during the rotation movement.
The publication by H. Taub et al., “Principles of Communication Systems”, 2nd edition, McGraw-Hill Publishing Company, 1986, pages 682-719 gives a general overview of basic principles of communication systems, whereby the possibility of the use of a time division multiplexing technique is mentioned.